Mutt, I just did 2 today! BTW every US Major does them everyday here in ZRH/LSZH. I'm pretty sure that you also have some of them in the States but you're too sure about yourself that you cannot recall!
The fact that the UAL pilot performed his take off in the end (without the ship left its harbour i presume) is a proof that it was ok/legal/operational wise/not dangerous/a victory of common sense (tick if applicable). Since it was one of the above, he was missing some important information before his final decision. Maybe that you could avoid the obstacle visually?
I'm not sure if you still know how you calculate TO performance, but before you just clicked on PC programs, you had runway tables with obstacle lists. The list consists of all limiting obstacles with the related distance. If you have that knowledge you can very easily determine if and what obstacle is limiting. (I had a look at a satelite picture of Logan airport and I assume that the boat anchored in the harbour opposite the parallel runways about half a mile away from the runway end.)
Be it as it is, yes, DC-ATE, I don't know anything about the actual case. I'm merely stating that I'm sooo glad I don't have to share the cockpit with one of you guys!
Dani